This is the 315th most frequent Polish word.
zwłaszcza
"Zwłaszcza" means "especially" in English.
Here, 'zwłaszcza' is used to highlight a specific item within a broader category that is being particularly emphasized.
Lubię wszystkie owoce, zwłaszcza jabłka.
I like all fruits, especially apples.
'Zwłaszcza' introduces a specific time period to emphasize the significance of the following condition.
Zwłaszcza zimą, ważne jest noszenie ciepłych ubrań.
Especially in winter, it is important to wear warm clothing.
In this sentence, 'zwłaszcza' is employed to specify a subgroup that is particularly relevant to the statement.